On Wed, Jun 01, 2011 at 08:16:44AM -0700, Richard Henderson wrote:
On 06/01/2011 07:29 AM, Avi Kivity wrote:
On 06/01/2011 05:01 PM, Richard Henderson wrote:
err = dev->mmu->translate(dev, addr,&paddr,&plen, is_write);I see you didn't take my suggestion for using an opaque callback pointer. Really and truly, I won't be able to use this as-is for Alpha.
Rather than opaques, please pass the DMA engine itself and use container_of().
The dma engine object is currently sitting in the PCIBus structure. Which is private, and can't be extended by a host bridge implementation.
The entire code could be re-arranged, true, but please suggest something reasonable.
We should be removing opaques, not adding them.
See my followup elsewhere. Opaques *can* be cleaner than upcasting, particularly if there are too many hoops through which to jump.
So, in the meantime, I've also done a version of Eduard's earlier patches, with added support for the PAPR hypervisor managed IOMMU.
I have also significantly reworked how the structure lookup works, partly because in my case I'l looking at IOMMU translation for non-PCI devices, but I think it may also address your concerns. I'm still using upcasts, but there are less steps from the device to the IOMMU state.
I've been sick and haven't had a chance to merge my stuff with Eduard's changes. I'll post them anyway, as another discussion point.